Continuous assessment of labour pain using handgrip force

Area of Science:

• Obstetrics and Gynecology
• Pain Management
• Biomedical Engineering

Background:

• Conventional pain scales like the numerical rating scale (NRS) have limitations for assessing dynamic pain during labor.
• Continuous pain evaluation using voluntary actions, such as handgrip force, presents an alternative for labor pain monitoring.
• Optimizing remifentanil administration for obstetric analgesia can be achieved through dynamic pain measures.

Purpose of the Study:

• To determine if continuous handgrip force monitoring can measure labor pain during contractions.
• To assess the correlation between handgrip force measurements and patient-reported pain intensity on the NRS.

Main Methods:

• An observational, single-center study involving 43 parturients.
• Handgrip force was measured using a calibrated dynamometer during early and late labor.
• Pain intensity was simultaneously recorded using the dynamometer and the NRS.

Main Results:

• Dynamometer readings correlated with external tocogram recordings of contractions.
• Handgrip force showed a moderate correlation with NRS pain scores.
• Mean handgrip force during contractions yielded the highest correlation (Pearson's r=0.67).

Conclusions:

• Handgrip force measured by a dynamometer enables continuous assessment of labor pain intensity and duration.
• This method can optimize patient-controlled remifentanil for obstetric analgesia.
• Dynamic pain assessment via handgrip force is applicable to other conditions with highly variable pain.